diff options
| author | Yu-cheng Yu <yu-cheng.yu@intel.com> | 2016-05-20 10:47:08 -0700 |
|---|---|---|
| committer | Ingo Molnar <mingo@kernel.org> | 2016-06-18 10:10:19 +0200 |
| commit | 99aa22d0d8f70d9317727ab40c85b2ead740a6ca (patch) | |
| tree | 34a01084331465f07c9fb42715bdad32e0ec59ac /arch/x86/include/asm/fpu | |
| parent | 7d9370607d28afd454775c623d5447603473a3c3 (diff) | |
x86/fpu/xstate: Copy xstate registers directly to the signal frame when compacted format is in use
XSAVES is a kernel instruction and uses a compacted format. When working
with user space, the kernel should provide standard-format, non-supervisor
state data. We cannot do __copy_to_user() from a compacted-format kernel
xstate area to a signal frame.
Dave Hansen proposes this method to simplify copy xstate directly to user.
This patch is based on an earlier patch from Fenghua Yu <fenghua.yu@intel.com>
Originally-from: Fenghua Yu <fenghua.yu@intel.com>
Signed-off-by: Yu-cheng Yu <yu-cheng.yu@intel.com>
Reviewed-by: Dave Hansen <dave.hansen@intel.com>
Cc: Andy Lutomirski <luto@kernel.org>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: Dave Hansen <dave.hansen@linux.intel.com>
Cc: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Fenghua Yu <fenghua.yu@intel.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Oleg Nesterov <oleg@redhat.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Quentin Casasnovas <quentin.casasnovas@oracle.com>
Cc: Ravi V. Shankar <ravi.v.shankar@intel.com>
Cc: Sai Praneeth Prakhya <sai.praneeth.prakhya@intel.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/c36f419d525517d04209a28dd8e1e5af9000036e.1463760376.git.yu-cheng.yu@intel.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>
Diffstat (limited to 'arch/x86/include/asm/fpu')
| -rw-r--r-- | arch/x86/include/asm/fpu/xstate.h | 1 |
1 files changed, 1 insertions, 0 deletions
diff --git a/arch/x86/include/asm/fpu/xstate.h b/arch/x86/include/asm/fpu/xstate.h index 16df2c44ac66..d812cf361282 100644 --- a/arch/x86/include/asm/fpu/xstate.h +++ b/arch/x86/include/asm/fpu/xstate.h @@ -47,5 +47,6 @@ extern void update_regset_xstate_info(unsigned int size, u64 xstate_mask); void fpu__xstate_clear_all_cpu_caps(void); void *get_xsave_addr(struct xregs_state *xsave, int xstate); const void *get_xsave_field_ptr(int xstate_field); +int using_compacted_format(void); #endif |